Oral compositions such as toothpastes, gels and mouth washes are designed to loosen and remove plaque in conjunction with a regular toothbrushing regimen. Dental plaque is present to some degree, in the form of a film, on virtually all dental surfaces. It is a byproduct of microbial growth, and comprises a dense microbial layer consisting of a mass of microorganisms embedded in a polysaccharide matrix. Plaque itself adheres firmly to dental surfaces and is removed only with difficulty even through a rigorous brushing regimen. Moreover, plaque rapidly reforms on the tooth surface after it is removed. Plaque may form on any part of the tooth surface, and is found particularly at the gingival margin, in cracks in the enamel, and on the surface of dental calculus. The danger associated with the formation of plaque on the teeth lies in the tendency of plaque to build up and eventually produce gingivitis, periodontitis and other types of periodontal disease, as well as dental caries and dental calculus.
It is known to the art to incorporate antimicrobial agents in oral compositions wherein these agents destroy or inhibit oral bacteria. Other agents are also incorporated in the oral composition to enhance the efficacy of the antimicrobial agents. For example, it is known to incorporate enzymes in oral compositions which disrupt or interfere with plaque formation and bacterial adhesion to tooth surfaces. Examples of such enzymes include glucose oxidase, galactose oxidase, lactose peroxidase, lactoferrin, lysozyme, proteolytic enzymes, pancreatic enzymes, bacterial enzymes (such as those obtained from Bacillus subtilis) lipolytic enzymes, dextranases (such as those from Penicillin funiculosium), and mixtures thereof.
Certain enzymes, as for example, proteolytic enzymes, such as papain, that enhance antibacterial efficacy at the levels wherein enhancement is observed, have been found to contribute to flavor (taste) problems whereby oral care products in which such enzymes are incorporated have limited acceptability for consumers. For example, the enzyme papain, which is naturally extracted from fruit, contains residual levels of impurities so that when papain is incorporated in an aqueous dentifrice or mouthwash, the impurities present adversely impact key consumer sensorial perceptions.
Attempts made to utilize flavoring ingredients to “mask” the taste problem and particularly the meaty notes introduced by these impurities, have met with limited success. There is therefore a need in the art for oral compositions imparting antiplaque and anti-malodor benefits in which enzymes are incorporated to provide a product of acceptable taste.